\begin{tikzpicture}[
    node distance = 2cm and 2cm,
    N/.style = {circle, draw, font=\Large, minimum size=1.1em},
    every edge/.style = {draw, -> , semithick, shorten >=2pt},
    every edge quotes/.style = {auto=right, inner sep=2pt}
    ]
    \node [N] (2) at (0,0) {2};
    \node [N] (3) [right of=2] [label=right:{-}] {3};
    \node [N] (4) [below of=2] {4};
    \node [N] (5) [right of=4] [label=right:{-}] {5};
    \node (占位1) at ([xshift=-2em]2) {};
    \node (占位2) at ([xshift=-2em]4) {};
    
    \path (占位1.west) edge [->] (2)
        (占位2.west) edge [->] (4)
        (2) edge [->] node [above] {a} (3)
        (2) edge [->] node [left] {a} (4)
        (4) edge [bend right] node [right] {$\varepsilon$} (2)
        (4) edge [->] (5);
    
\end{tikzpicture}
